“Blessed are those who have been persecuted because of their righteousness, for theirs is the Kingdom of Heaven.” Many of the people who have been persecuted died in the persecution, but they are promised “the Kingdom of Heaven,” i.e., everlasting life in Christ’s wonderful future kingdom on earth. In this context, “righteousness” in the phrase “because of their righteousness” refers to both a believer’s righteous standing in the sight of God and the righteous acts that they do. The primary emphasis of “righteousness” in this verse is “righteous acts,” because it is the righteous acts of godly people that draws the attention of ungodly people and incites them to persecute the godly. Thus, in that sense this verse is very similar to 2 Timothy 3:12, that everyone who lives a godly life will be persecuted. Also, however, on a spiritual level, the Devil and his people cannot be at peace with people who have a right standing in the sight of God (are spiritually “righteous”) and so persecute them for that reason also.
[For more on “righteousness” having the meaning of doing what is right or just (“justice”), see commentary on Matt. 5:6. For more on the meaning of “righteousness” and that word family, see commentary on Rom. 3:22. For more on Christ’s future Millennial Kingdom on earth, see Appendix 3, “Christ’s Future Kingdom on Earth”].